Films or sheets of polymeric barrier materials are formed into a finished package or "film package" such as a pouch by various techniques. For instance, by forming heat or adhesive seals about the periphery of the shape to be formed into a pouch. For example, if a square pouch is desired, a rectangular film twice the desired length of the pouch is folded, the two parallel sides of the periphery (perpindicular to the fold) heat or adhesive sealed, or, the two parallel sides and the fold are heat or adhesive sealed, the food or other material to be packaged inserted therein, and then the remaining open side of the periphery is heat or adhesive sealed. Another method for making a pouch is by sealing on three sides face-to-face films, filling the thus formed open pouch with food or whatever material is to be packaged therein, and then sealing the fourth side. For background on pouches or bags and their production, reference is made to U.S. Pat. Nos. 4,190,477, 4,311,742, 4,360,550, 4,424,256 and 4,557,377, each of which being hereby incorporated herein by reference.
With respect to means for opening pouches or packages, or to laser scoring, or to laminate structures, reference is made to the following:
U.S. Pat. Nos. 3,313,642, 3,404,988, 3,608,815, 3,626,143, 3,693,785, 3,790,744, 3,909,582, 3,925,591, 3,986,640, 4,172,915, 4,217,327, 4,236,652, 4,356,375, 4,407,873, 4,543,279, 4,549,063, 4,557,377, 4,571,340, 4,656,094, 4,698,246, 4,762,514, 4,765,999, 4,778,058, 4,784,885, 4,785,937, 4,788,105, 4,808,421, 4,834,245, 4,880,701, 4,894,115, 4,934,245; and, Japanese Utility Model Publications Nos. 54-22484 and 51-48775. Reference is also made to U.S. Pat. No. 4,681,781, German Patent Document 2803074, UK 973,109 and EPA 0357841, of record in predecessor application Ser. No. 07/550,738.
The problem encountered by the end user of the food or material within the pouch is how to open the pouch. The pouches are usually formed from tough or strong polymeric barrier materials so the pouches do not open easily. One method for opening such pouches is to manually rip at the pouch which usually results in its contents spilling all about. Another method is simply cutting open the pouch with a scissor, knife or other sharp object. It is desirable to be able to neatly open a pouch without the need to use a cutting instrument. Furthermore, the problem of how to open a pouch is really two-fold: The first problem is how to initiate the opening. The second problem is providing control of the opening across the entire pouch.
To meet this desire of being able to open a pouch without a cutting instrument, some have proposed packages having an opening notch such V-or I-shaped notch or notches, or a tearing zone, see e.g., U.S. Pat. Nos. 4,934,245, 3,404,988. U.S. Pat. No. 3,693,785 relates to a wrapping material containing regenerated cellulose which has a portion thereof which is more frangible than the remainder thereof. Likewise, U.S. Pat. No. 3,986,640 deals with a flexible package having a cut pattern, which when bent along the cut pattern, causes the package to open and the flowable contents therein to dispense. U.S. Pat. No. 4,217,327 relates to forming a score line along a predetermined line in the surface of a plastic film to form a tear line. And, U.S. Pat. No. 4,236,652 relates to a package having a cut score area to rupture open the package upon bending.
These previous proposals have not overcome the problem. Notches, cut patterns or tear lines can produce an opening which is easily propagated without any control. Further, notches, cut patterns or tear lines produce areas of weakness in the package, which, when stressed accidentally, e.g., during handling or shipping, can become an unintended opening which is easily propagated. That is, these proposals have not adequately resolved the problem of initiating an opening only when desired and of controlling the opening across the entire package.
Furthermore, these proposals have presented manufacturing problems. For instance, the problem of properly locating the notch, cut pattern or tear line in a position where the consumer desires to open the package. If not properly positioned, the resulting package can be worse than if no such notch, cut pattern or tear line had been provided: The consumer must still resort to a sharp object to open the package, but it is weakened at some point (due to the mispositioned notch, cut pattern, or tear line). In addition, opening features such as those on cigarette packs require a separate opening tape which means that it is more costly to manufacture the package because it requires a separate material (the tape) and a complicated process.
Roughening an area of the package is another type of proposal to open a package without the need for a cutting instrument. U.S. Pat. No. 3,313,642 relates to a process of modifying the surface properties and polyolefin film.
U.S. Pat. No. 4,778,058 provides a pouch from a film of two plastic layers. A discreet area of the first layer, corresponding to a folded portion of the resultant pouch, is surface toughened prior to lamination to the second layer. The irregularities from roughening are filled with the plastic material of the second plastic layer. The film of the two layered film is heat-sealed into a pouch. The surface roughening is at a position on the first layer of the film other than the portion thereof to be heat sealed. While U.S. Pat. No. 4,778,058 may provide for tear initiation, it still fails to provide for control of the tear as is desired by the end user.
U.S. Pat. No. 4,543,279 relates to a film product, such as a sealed bag, wound film or adhesive tape, having a plurality of random scratches or cuts formed along the edges and oriented toward the other side of the film. In a bag of U.S. Pat. No. 4,543,279, the scratches are formed on the longitudinal edge portion of the bag, outside of the seals thereof, or on the longitudinal edge portion outside of the seal and a central line inside the seal. While placing scratches on a central line inside the seal may provide for tear initiation, the placement of the scratches outside of the seals may not adequately provide for tear initiation as the user must still rip through the seals. And, no provision is made for tear control.
U.S. Pat. No. 3,608,815 relates to an opening aid for packages made from at least one oriented material. The opening aid consists of minutely expanding the oriented material at a plurality of points within an area pattern which will be a fold of the package. U.S. Pat. No. 3,608,815 simply provides tear initiation like the previously discussed notch or cut techniques. However, U.S. Pat. No. 3,608,815 chalks up tear control to the nature of the materials of the package, stating that oriented materials "tear in an essentially straight line" while cellophane will tear without directional control. Thus, U.S. Pat. No. 3,608,815 does not adequately provide tear control.
Japanese Utility Model Publication No. 54-22484, published Aug. 6, 1979 (Application No. 50,68727 dated May 23, 1975; Early Disclosure No. 51-150915, dated Dec. 2, 1976), relates to a bag having seals with tear-initiating lines. The tear initiating lines consist of ordered, successively smaller pinholes or notches extending from the outer edge of the seal and terminating at the center of the seal so that the inner half of the seal is the same as an ordinary seal. It is stated in this publication that the holes or notches are not to extend all the way into the enclosed part of the bag, i.e., across the entire width of the seal, because to do so will impair the strength and the airtightness of the seal. Further, this publication poses manufacturing problems which it leaves unaddressed. To effect the tear-initiating line, the films of the bag must be selectively cut or notched: The cuts or notches are organized along lines and are of varying size and extend only through one-half of the seal. Thus, this publication calls for a very complicated manufacturing process.
Japanese Patent Publication No. 51,48775, published Dec. 22, 1976 (Application No. 49-49804 dated May 7, 1974; Early Disclosure No. 51-16346, dated Feb. 9, 1976), deals with placing minute scars, embossment or scratches along the center line of a laminate plastic film which is then slit lengthwise along the center line to make two adhesive tapes. The problems of tear initiation and tear control in the opening of packages are not addressed in this publication.
Bowen, U.S. Pat. Nos. 3,909,502 and 3,790,744, Fry, U.S. Pat. No. 3,626,143, Ang, U.S. Pat. No. 4,549,063, Josephy, U.S. Pat. No. 4,356,375 and Yoshida, U.S. Pat. No. 4,762,514 all relate to laser scoring and each of these U.S. Patents is hereby incorporated herein by reference.
Bowen, U.S. Pat. No. 3,790,744 relates to forming one line of weakness in at least one but not all layers of a multilayer structure by preferentially vaporizing with a beam of radiant energy a line in at least one layer which is not the most proximate layer in relation to the source of radiant energy. Bowen, U.S. Pat. No. 3,909,582, deals with forming a line of weakness defining a tear path in a multilayer laminate by scoring with a beam of radiant energy the most proximate layer in relation to the source of radiant energy. While these patents may speak of forming one or more lines of weakness or at least one line of weakness, neither of these patents indeed teaches or suggests forming a plurality, e.g., two or three, parallel, laser scores to provide the easy-open feature of the present invention. Further, neither of these Bowen patents teaches or suggests the multilayer laminates of the present invention, or the manufacturing advantages of the present invention.
Fry, U.S. Pat. No. 3,626,143, similarly relates to focusing a single beam of laser light upon a thermoplastic substrate so as to form a single score. Fry fails to teach or suggest forming a plurality of parallel scores, or the laminates or advantages of the present invention.
Ang, U.S. Pat. No. 4,549,063 deals with forming a crack and peel feature on the backing of an adhesive laminate by providing the backing with one or more non-linear, discontinuous, preferably sine-wave geometric pattern, lines, preferably by a laser. Ang fails to teach or suggest forming a plurality of parallel, linear or substantially straight, and preferably continuous scores as herein to provide an easy-open feature to a package; and, Ang fails to teach or suggest the laminates and advantages of the present invention. Josephy, U.S. Pat. No. 4,356,375, also relates to forming a line of weakness in the protective backing of an adhesive laminate, and suffers from the same deficiencies of Ang, Fry and Bowen.
Yoshida, U.S. Pat. No. 4,762,514 deals with laser scoring a beverage pouch in a particular pattern to facilitate rupture to introduce straw, e.g., scores in an "X" shape, on a "Y" or a star shape or a series of parallel cuts. However, this patent fails to teach or suggest a package such a pouch having a plurality of parallel, linear or substantially straight scores which extend across the entire width of the package, near or adjacent to a seal thereof, to provide an easy-open tear feature on said package as provided for herein; and, Yoshida fails to teach or suggest the laminates and advantages of the present invention.
Eichelberger, U.S. Pat. No. 4,894,115, incorporated herein by reference, is concerned with the fabrication of integrated chip assemblies having a dielectric polymer layer thereover which is laser-scored to access the chip for electrical connections. This patent is disclosed and incorporated herein because it deals with a use of a laser, but, it is not considered pertinent and is considered non-analogous to the present invention.
The remaining patents disclosed herein deal with diverse multilayer packaging laminates, and, either individually or in any combination fail to teach or suggest the laminates or advantages of the present invention. Certain of these patents, e.g., U.S. Pat. Nos. 4,407,873, 4,785,937, 4,808,421 or 4,571,340 may mention retortable, microwaveable or ovenable containers, but do not disclose or suggest the mix and bake pouch of the present invention.
Thus, heretofore, a package, preferably a pouch, having an easy-open tear feature comprising a plurality of linear, or substantially straight, e.g., two or three preferably continuous laser scores extending across the entire width of said pouch and preferably disposed near or adjacent to a seal thereof, has not been disclosed or suggested. Nor has such a scored pouch from a multilayer structure, e.g., a laminate, comprising from outer layer to inner layer, Polyester/Polyethylene/Polyester/Polyethylene, e.g. white block polyethylene/coextrusion sealant film, e.g., at least one layer high density polyethylene, e.g., white colored/linear low density polyethylene wherein the scores can extend through the first two layers of polyester and polyethylene, but not through the third, or internal, polyester layer, been disclosed or suggested.
Nor has a structure comprising (outer) polyester/polyethylene/high density polyethylene/linear low density polyethylene (inner) been disclosed or suggested. Nor has such a structure in the form of a pouch having a plurality of linear, or substantially straight, preferably continuous laser scores extending across the entire width of said pouch and disposed near or adjacent to a seal thereof, been disclosed or suggested.
Further, a large pouch, having an easy-open tear feature of a plurality of parallel, linear or substantially straight, preferably continuous scores extending across the entire width of said pouch, wherein one can mix ingredients, e.g., cake mix, such as with a mixer; and, once mixed, rip away the top portion of the pouch using the score lines and then employ the remainder of the pouch as a pan to bake in, has not been disclosed or suggested.
It is therefore an object of this invention to provide the pouches and multilayer structures or laminates which have heretofore not been disclosed or suggested. It is also an object of this invention to provide manufacturing advantages from the application of a plurality of parallel, linear or substantially straight scores across the entire width of a pouch.